Question

Suppose that y varies directly with x , y= 15 and when x=6. write a direct variation equation

Answer 1

`y = (5)/(2)x`

Explanation:

Given

Variation: Direct from y to x:

`y\ \alpha\ x`

`y =15; x = 6`

Required

Write the equation

`y\ \alpha\ x`

Express as an equation

`y = kx`

Where k is the constant of variation

Substitute
`y =15; x = 6`

`15 = 6k`

Solve for k

`k = (15)/(6)`

`k = (5)/(2)`

Substitute
`k = (5)/(2)` in
`y = kx`

`y = (5)/(2)x`